Oil well derrick structure



July 10, 1945. H. J. WOOLSLAYER 2,330,094

OIL WELL DERRICK STRUCTURE Filed Oct. 29, 1943 Patented July 10, 1945 OIL WELL DERRICK STRUCTURE Homer .1. Woolslayer, Tulsa, Okla., assignor to LeeC.

Moore a; Company, Inc.,

Pittsburgh, Pin,

a corporation of Pennsylvania Application October 29, 1943, Serial No. 508,109

6 Claims. (Cl. 18916) This invention relates to oil well derrick structures, and more particularly to gin poles and a method of erecting them at the top of derricks.

In order to lift a heavy crown block to the top of an oil well derrick it is necessary to Provide some kin'd of superstructure or supplementary derrick above the main derrick to support thecables by which the crown block is raised. This superstructure is commonly called a sin pole although it is more of a fabricated structure or mast than a pole. The building of a gin pole on top of a derrick is diflicult and dangerous. The workmen have hazardous footholds and have to lift heavy structural members up into position. Furthermore, the gin pole substantially covers the top of the derrick and itself interferes with the raising and setting of the crown block. This is particularly true of two-layer crown blocks where the top layer must be raised first and then held out of the way while the bottom layer is being raised and mounted in Position, after which the top layer'is lowered onto the bottom layer. This is diiilcult to do with a conventional gin pole because its structure surrounds the top of the derrick and interferes with holding the top layer of the crown block out of the way temporarily.

It is among the obiectsof this invention to provide a gin pole that can be prefabricated on the ground and then quickly and safely mounted in operative position at the top of a derrick, and which obstructs only one side of the derrick top whereby plenty of space is left for crown block mounting operations. I v

In accordance with this invention a gin pole is prefabricated by constructing it on the ground, either in; factory or at the well site, and then is pulled up the outside of the derrick bottom end up. That end of the pole is hinged to the side of the derrick near its top with the rest of the pole hanging down the outside of the derrick. The free end of the sin pole is then swung upwardly by a cable into upright position beside the derrick above which it projects the desired height. The pole is fastened to the side of the derrick above its 1 hinge and thereby locked in place. To support the block and tackle by which the crown block is to be raised, the topof the pole has a laterally projecting portion that extends inwardly above the top of the derrick and terminates in a horizontal beam above the center of the derrick. The upright members of the sin pole thus are outside of the top area of the derrick so that three sides of the top are left unobstructed and open for the work connected with mounting the crown block in place. The'top layer of a two-layer crown block can be slid over to one end of the gin poles horizontal beam while the bottom layer of the block is being raised.

The preferred embodiment of this invention is illustrated in the accompanying drawing in which Fig. l is a side view of my gin polemounted in operative position at the top of an oil well derrick; and Fig. 2 is a side view of the derrick and pole taken from the gin pole side of the structure.

Referring to the drawing, a gin pole is formed principally. from a mast i prefabricated from structural steel members on the ground, by which is meant that it may be constructed at the well site or in a factory. The end of the mast that is to be at the bottom is provided with hinge connections, and the other end has laterally projecting members 2 that are connected at their outer ends by a transverse beam 3 and are braced by diagonal braces 4, as shown in Fig. 1. The side of the mast nearest beam 3 is straight from the lateral members 2 and 4 to the opposite end, but the lower portion of the opposite side of the mast is inclined downwardly and inwardly to the hinge connections. The other two sides of the mast are inclined upwardly toward each other as shown in When the oil'wellderrick 6 is erected, it is provided on one side with a pair of outwardly pro- Jecting hinge brackets I mounted on its legs at about the second girt from the top of the derrick. A block or pulley 8 is'suspended temporarily from the top girt and a cable 9 passed over it. One end of the cable is connected the mast lying on the ground straight side up and the opposite end of the'cable is secured to a suitable winding drum. The cable is then reeled in to hoist the gin pole, with its lower end uppermost as shown by broken lines in Fig. 2, up the outside of the derrick until its hinge connections reach the hinge brackets 1. A line may be connected to the depending end of the gin pole to help guide it up the derrick. The shape of the bottom of themast permits it to lie fairly close to the derrick while being raised. Hinge pins are inserted in the hinge brackets and cooperating openings in the gin pole to connect it to the derrick so that further pull on the cable will swing the free end of the pole outwardly and upwardly through an arcuate path until the pole is in upright position. To secure the pole in this posito the central portion of tlon, locking pins are inserted in registering openwill be of no further use unless it later is decided" completed after the gin pole is located in operative position. I

In using this gin pole to lift a two-layer crown block into position, a sling over beam I can be connected to the elevated top layer which then can be moved along to one end or the beam and supported by the sling "out of the way the tackle thus freed for raising the bottom layer of the crown block. This procedure is possible because there are no vertical members of the gin pole at the ends of beam 3. In fact, the gin pole obstructs only one side of the top of the derrick, thereby leaving the other three sides open which gives ample working space.

The extra cost and danger or fabricating a gin pole on top of a derrick are avoided by the use of my. prefabricated gin pole.

According to the provisions of the patent statutes, I have explained the principle and construction of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, withinthe scope of the apaseaoos pended claims, the invention may be practiced otherwise than as specifically illustrated and described.

Iclaim:

- 1. A preassembled gin pole adapted to be mounted at the top of an oil well derrick, said pole comprising a skeleton mast structure substantially as wide as the top portion of the derrick and having a laterally projecting portion at one end, means connected to the outer end of said portion for supporting block and tackle, means at the oppositeend of said mast for hinging it at horizontally spaced points to one side of the derrick near the top of the latter with the mast hanging down the outside of the derrick and with said lateral portion projecting outwardly, said mast being adapted to be swung up into upright position to locate said supporting means over the top of the derrick, and means on said mast above said hinging means for fastening it in said position to the derrick.

2. A preassembled gin pole adapted to be mounted at the top of an oil well derrick, said pole comprising a skeleton mast structure substantially as wide as the top portion of the derrick and having horizontally spaced members projecting laterally from two opposite sides, a horizontal beam connected to the outer ends of said members for supporting block and tackle,

means at the opposite end oi said mast for hinging it at horizontally spaced points to one side of the derrick near the top of the latter with the mast hanging down the outside of the derrick and with said lateral portion projecting outstantially as wide as the top portion of the derrick and having a laterally projecting portion at one end, means connected to the outer end of said portion for supporting block and tackle,

down the outside of the derrick and with said lateral portion projecting outwardly, said mast being adapted to be swung up into upright position to locate said supporting means over the top of the derrick, said mast tapering upwardly from its hinged end to substantially the same extent as the adjoining side of the derrick, and horizontally spaced brackets on said mast above said hinging means for fastening it in said position to the derrick.

4. A preassembled gin pole adapted to be mounted at the top of an oil well derrick, said pole comprising a skeleton mast structure substantially as wide as the top portion of the derrick and having a laterally projecting portion at I one end, means connected to the outer end of said portion for supporting block 'and tackle, means at the opposite end 01' said mast for hinging it at horizontally spaced points to one side of the derrick near the top oi. the latter with the mast hanging down the outside ofmierrickmd with said lateral portion projecting outwardly, the side of the mast between said hinging means and lateral portion being straight and the opposite side of the mast being straight for part of its length and then being inclined inwardly toward said hinging means, saidmast being adapted to be swung up into upright position to locate said supporting means over the top of'the derrick, and means on said mast above said hinging means for fastening it in said position to the derrick.

5. An oil well derrick structure comprising a derrick, a preassembled skeleton mast structure substantially as wide as the top portion of the derrick and having a laterally projecting portion at one end, means for hinging the opposite end of'the mast at horizontally spaced points to one side of the derrick near the top of the latter with the mast hanging down the outside of the derrick and with said lateral portion projecting outwardly, means for sw nm the mast up into upright position to locate said lateral portion over the top of the derrick, and means above said hinging means for fastening the mast to the derrick in upright position for use as a gin pole, the end of said lateral portion being provided with a horizontal beam extending across the center line oi. the derrick.

6. An oil well derrick structure comprising a derrick, a preassembled skeleton mast" structure substantially as wide as the top portion .of the derrick and having a laterally projecting portion at one end, means for hinging the opposite end of the mast at horizontally spaced points to one side of the derrick near the top of the latter with the mast hanging down the outside of the derrick and with said lateral portion projecting outwardly, means for swinging the mast up into un isht.

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